code: def test_concat_function(self):
      function_name = "CONCAT"
      execute_query_fetch_all(
          self.evadb, f"DROP FUNCTION IF EXISTS {function_name};"
      )
      create_function_query = f"""CREATE FUNCTION IF NOT EXISTS {function_name}
          INPUT  (inp ANYTYPE)
          OUTPUT (output NDARRAY STR(ANYDIM))
          TYPE HelperFunction
          IMPL 'evadb/functions/helpers/concat.py';
          """
      execute_query_fetch_all(self.evadb, create_function_query)
  
      execute_query_fetch_all(
          self.evadb, "DROP FUNCTION IF EXISTS UPPER;"
      )
      create_function_query = """CREATE FUNCTION IF NOT EXISTS UPPER
          INPUT  (inp ANYTYPE)
          OUTPUT (output NDARRAY STR(ANYDIM))
          TYPE HelperFunction
          IMPL 'evadb/functions/helpers/upper.py';
          """
  
      execute_query_fetch_all(self.evadb, create_function_query)
      query = "SELECT CONCAT(UPPER('Eva'), 'DB');"
      output_batch = execute_query_fetch_all(self.evadb, query)
      self.assertEqual(len(output_batch), 1)
      self.assertEqual(output_batch.frames["concat.output"][0], "EVADB")
  
      query = "SELECT CONCAT(input, '.com') FROM Test;"
      output_batch = execute_query_fetch_all(self.evadb, query)
      self.assertEqual(len(output_batch), 1)
      self.assertEqual(
          output_batch.frames["concat.output"][0], "EvaDB.com"
      )
  
file_path: evadb/test/integration_tests/long/functions/helpers/test_str_helper_functions.py
imports: import unittest
  from test.util import get_evadb_for_testing
  from evadb.server.command_handler import execute_query_fetch_all
label_desc: Use image node_id 5 for calling the StrHelperTest obj's underlying member method code with example usage: obj.test_concat_function() without return types